Two problems related to gasoline fuel system have been reported for the 2009 Mercury Mariner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Mercury Mariner based on all problems reported for the 2009 Mariner.
Car engine stopped while driving at a low (10-20 mph) speed. Second time this happened. First time on 2011 replaced throttle body then. It happened again 12/31/2013. Ford service said throttle body needs to be replaced again.
While driving the Mariner at 45 mph on a busy street, the engine went into limp mode, lost all acceleration and slowed to 5 mph. I was nearly rear-ended by the truck behind me and was forced to pull up onto a sidewalk, damaging my tire. Pulled the codes on the car and got a p111 code. Did some searching on the internet and found that this is a common issue and an extreme safety hazard. I was very happy that I was the driver, and not my 16 year old daughter!!! this is the second safety issue we have had with this car in the last month -- earlier the power steering went out, again without any warning in traffic.
| Tank Assembly problems | |
| Gasoline Fuel System problems |